Inner Thames Estuary Feasibility Study 1: ENVIRONMENTAL IMPACTS
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Airports Commission Inner Thames Estuary Feasibility Study 1: ENVIRONMENTAL IMPACTS July 2014 Inner Thames Estuary Feasibility Study 1: Environmental Impacts Document Control Sheet Document Control Sheet BPP 04 F8 Version 16; October 2013 Project: Estuary Study No. 1: Environment Client: Airports Commission Project No: B146007 Document title: Final for Consultation Ref. 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Inner Thames Estuary Feasibility Study 1: Environmental Impacts Executive Summary Executive Summary (i) Background In December 2013, the Airports Commission identified that while an Inner Thames Estuary location had the potential to provide a significant reduction in the noise impacts compared to most of the phase 1 options and create economic and regeneration activity in north Kent and Essex, it also presented some clear challenges on which further information was needed before a decision could be reached on whether to short-list such a proposal for phase 2. One of these challenges included understanding further the adverse effects of constructing and operating an airport in an Inner Thames Estuary location, a location of clear and distinct nature and conservation value. In particular, identifying and understanding the issues affecting the Natura 2000 network of designated sites, and the wider environmental impacts on estuarine processes, morphology, flood risk, landscape and cultural heritage. The purpose of this report is to fulfil the Terms of Reference (ToR) for the environmental impacts study, as set out in the final ToR published by the Airports Commission in March 2014. Comments received from both the consultation on the draft terms of reference and the call for evidence have been included as part of the study, where it has been appropriate and relevant to do so. (ii) Baseline environment The Inner Thames Estuary around the Hoo Peninsula comprises extensive areas of intertidal habitat including saltmarsh and mudflat, which support high numbers of internationally important bird species. These habitats provide a vital food resource for overwintering migratory birds. In addition, there are large areas of coastal floodplain grazing marsh in the north-western and eastern peripheries of the Peninsula, which support substantial populations of breeding birds. This habitat is crossed by many drains and ditches which provide feeding opportunities and roosting grounds for birds. Saline lagoons are present in the west of the Peninsula and are also used by a wide variety of wading birds. Estuarine processes are important in supporting the habitats and species of the Thames Estuary. Fine grained sediments play an important role in ecosystem processes within the estuary as they are naturally deposited on mudflats and saltmarshes. The Greater Thames Estuary is under pressure from development and anthropogenic disturbance as well as the longer term effects of climate change. The Environment Agency established the Thames Estuary 2100 (TE2100) project to provide a plan to manage flood risk in the estuary over the next one hundred years. A key driver for this initiative was adaptation to the uncertain effects of climate change, with the prospect of changes in sea level; storm surge height and frequency; and river flows. As the TE2100 plan has identified a number of potential sites for managed realignment and habitat creation, it is not anticipated that the predicted plan and climate change impacts on the estuary’s habitats will lead to significant long term reductions in habitat area or populations of species they support. 2-1 Inner Thames Estuary Feasibility Study 1: Environmental Impacts Executive Summary (iii) Potential impacts and Mitigation or Compensation The key findings from the study on potential impacts and scope for mitigation or compensation are summarised below for each topic area. Ecology While there would be no direct impacts on priority habitats as defined under the Habitats Directive, all the airport options proposed would result in a large scale direct habitat loss to Thames Estuary and Marshes SPA and Ramsar sites (as a minimum 24% & 27% of designation areas). Some sites would also involve direct loss to the Medway Marshes SPA and Ramsar sites (0-4% of designation areas). Given the large scale of loss to the Natura 2000 sites, which would not be possible to mitigate in close proximity the sites mainly due to bird strike risk, geomorphology changes and flood risk, it is expected that any future appropriate assessment through the Habitats Regulations Assessment (HRA) would conclude that there are likely significant adverse effects on the Natura 2000 network. Under the steps of the HRA process, the proposals would, therefore, be required to progress to the Alternatives Solutions test. The Competent Authority (Secretary of State for Transport) would need to be certain that no alternative solutions existed, had considered the best scientific knowledge and taken into account the representations of Natural England and Environment Agency. If this test is passed it would need to be demonstrated that the proposals were needed for Imperative Reasons of Overriding Public interest (IROPI). In the event that the proposals were to be taken through the HRA alternative solution and IROPI steps, an acceptable package of compensatory measures would need to be developed. The compensatory measures would need to be created in advance and demonstrated to be adequate before losses occur. Key issues related to provision of adequate compensatory habitat include: The compensation measures would need to allow for the full impact of the airport, including in-combination effects, on the Natura 2000 sitesThere are a range of additional sources of direct and indirect impacts, which can lead to further losses to the function of habitats in and around the Hoo Peninsula. These are difficult to measure at this stage without detailed assessment, field data or modelling and include: - Bird strike management to reduce risk of bird strike to acceptable levels; - Morphological changes to the estuary: - Disturbance effects from airport operations and air traffic; and - Compensation areas for other developments that are displaced. A minimum of around 2130 hectares (ha) is likely to be needed for habitat compensation for the airport proposals and displacement of other compensatory habitat. An upper estimate of 6800ha attempts to capture some of the potential indirect losses. The road and rail links to the airport are also likely to result in additional direct losses to Natura 2000 sites and these are therefore likely to add to the total area required for compensation.